NHTSA says a heat shield in the car can rust, dislodge and cause the steering shaft to jam. It has received 5 complaints about the issue and knows of one injury. In that case, the steering froze as a driver entered a highway entrance ramp, causing the car to roll over and cause injuries.

Ford Motor Co. says it will cooperate with the NHTSA on the investigation.

Ford shares rose 17 cents to $17.47 in midday trading Friday. They have risen more than 11 percent in the past three months.